System and method for inspection of a sewer network

ABSTRACT

A system for inspection of a sewer network. The system comprises: a cleaning nozzle mounted on a hose; an inspection sled having a camera mounted thereon and a nozzle mounting section selectively engageable to the cleaning nozzle; and a position encoder configured to acquire position data representative of the position of the camera inside the conduit while the sled is moved inside the conduit by the movement of the cleaning nozzle and the camera captures images of the inner wall of the conduit. A method for inspection of a sewer network using the system is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35USC § 119(e) of U.S.provisional patent application(s) 63/109,626, the specification of whichbeing hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of sewer network inspection.More particularly, it relates to a system and a method for performingsewer network inspection, which leverages the components used for priorcleaning of the sewer line to move the inspection system used to performthe inspection and to determine the position of the inspection equipmentinside the sewer network while inspection is being performed.

BACKGROUND

In the field of conduit inspections, it is common practice to perform athorough cleaning of the conduits before performing conduit inspection.Such prior cleaning of the conduit is important to remove theaccumulated particles, wastes and/or debris, in order to allow thepassage of the inspection equipment inside the conduit and to perform amore detailed and accurate inspection. For example and without beinglimitative, the conduits being inspected can be sewer lines, waterlines, or the like, ranging between about 150 mm and about 1500 mm indiameter.

Currently known methods and systems for performing the prior cleaning ofthe conduits and the subsequent inspection thereof, use differentsystems for each of these two distinct phases of the process. Hence, acleaning system is commonly initially used to perform conduit cleaningand a distinct inspection system is commonly subsequently used toperform the inspection of the conduit, following the initial cleaningthereof. In more details, it is common to initially perform waterpressure cleaning of the conduit, using a cleaning assembly including aconduit cleaning nozzle (or sewer cleaning nozzle) mounted to a waterhose and moved longitudinally inside the conduit to project highpressure water onto the conduit wall and remove the accumulatedparticles, wastes and/or debris and to subsequently introduce aninspection robot in the conduit and move the inspection robot along thesection of the conduit to be inspected, to acquire images of the conduitwalls for this section.

Known systems and method using distinct components for performing thecleaning of the conduit and the subsequent inspection thereof, however,tend to suffer from several drawbacks. Indeed, the need for two distinctsystems being used one after the other, results in economic loss from,for example and without being limitative, increased equipmentacquisition costs, greater space required for transport of the equipmenttowards inspection sites, greater number of workers required for theoperation of the multiple systems, increase time for setting up,operating and setting out the equipment, etc.

In view of the above, there is a need for an improved method and/orsystem for inspection of a sewer network which, by virtue of its designand/or components, would be able to overcome or at least minimize someof the above-discussed prior art concerns.

SUMMARY OF THE INVENTION

In accordance with a first general aspect, there is provided a systemfor inspection of a sewer network. The system comprises a cleaningnozzle mounted on a hose; an inspection sled having a camera mountedthereon and a nozzle mounting section selectively engageable to thecleaning nozzle; and a position encoder configured to acquire positiondata representative of the position of the camera inside the conduitwhile the sled is moved inside the conduit by the movement of thecleaning nozzle and the camera captures images of the inner wall of theconduit.

In an embodiment, the position encoder is configured to determine theposition of the camera inside the conduit through measuring of themovement of the hose as the nozzle is moved inside the conduit, the hosebeing extended and retracted correspondingly in accordance with themovement of the nozzle inside the conduit.

In an embodiment the position encoder is mounted on a cleaning vehicle.The hose is connected to the cleaning vehicle and is selectivelyextended from the cleaning vehicle and winded back towards the cleaningvehicle in accordance with the forward and rearward movement of thenozzle inside the conduit. The movement of the hose is representative ofthe movement of the inspection sled inside the conduit, when theinspection sled is engaged to the cleaning nozzle.

In an embodiment, the position encoder is mounted on the inspectionsled. The position encoder is configured to determine the position ofthe camera inside the conduit through measuring of a rotative movementof a rotative member of a displacement assembly rotating along with themovement of the sled inside the conduit induced by the movement of thecleaning nozzle.

In an embodiment, the nozzle mounting section includes an electromagnetactivable to engage the cleaning nozzle to the nozzle mounting sectionof the sled.

In an embodiment, the nozzle mounting section includes a guiding funnelprojecting at a front end of the nozzle mounting section, the guidingfunnel being centered on the electromagnet.

In an embodiment, the sled includes a sled body and the nozzle mountingsection includes an engagement body pivotally mounted to the sled body,using a hinge allowing pivoting of the engagement body with regard thesled body.

In an embodiment, the inspection sled further comprises lightsconfigured to provide lighting of a at least a portion of a field ofview of the camera.

In an embodiment, the camera and the position encoder are configured togenerate time stamps. The corresponding time stamps associated topositions determined using the position encoder and to images capturedby the camera are used to associate images to corresponding positionsinside the conduit.

In accordance with another general aspect, there is also provided amethod for inspection of a sewer network. The method comprises the stepsof: moving a cleaning nozzle in a conduit to be inspected, the cleaningnozzle being mounted to a hose, at an end thereof; inserting a sledhaving inspection material mounted thereon in the conduit, theinspection material including a camera; engaging the cleaning nozzlewith the sled; moving the guiding nozzle in the conduit andcorrespondingly moving the engaged sled in the conduit; andsimultaneously to the sled being moved in the conduit by the movement ofthe guiding nozzle: capturing images of the inner wall of the conduitusing the camera mounted on the sled; and acquiring position datathrough monitoring of the movement of the sled using a position encoder.The method also includes the step of determining a capture position forat least a subset of the images of the inner walls of the conduitcaptured by the camera, using the position data.

In an embodiment, the method further comprises the steps of insertingthe cleaning nozzle in the conduit through a first manhole and insertingthe inspection sled in the conduit via a second manhole.

In an embodiment, the step of acquiring position data through monitoringof the movement sled using a position encoder comprises monitoring themovement of the hose.

In an embodiment, the step of inserting the sled in the conduitcomprises the sub steps of: engaging the sled to a guiding pole;lowering the sled in the conduit using the guiding pole; and disengagingthe guiding pole from the sled.

In an embodiment, the sub step of engaging the sled to a guiding poleincludes activating a pole engaging electromagnet and the sub step ofdisengaging the guiding pole from the sled includes deactivating thepole engaging electromagnet.

In an embodiment, the step of engaging the cleaning nozzle to the sledincludes activating a nozzle electromagnet.

In an embodiment, the step of engaging the cleaning nozzle to the sledincludes advancing the nozzle towards the sled and guiding the nozzleusing a funnel.

In an embodiment, the method further comprises the step of removing thesled from the conduit, via the first manhole.

In an embodiment, the method further comprises simultaneously to thesled being moved in the first manhole: capturing images of the innerwall of the first manhole using the camera mounted on the sled; andacquiring position data through monitoring of the movement of the sledusing the position encoder. The method also comprises determining acapture position for at least a subset of the images of the inner wallsof the first manhole captured by the camera, using the position data.

In an embodiment, the method further comprises the initial step ofcirculating the cleaning nozzle in the conduit in order to performcleaning of the conduit.

In an embodiment, the method further comprises generating time stampsfor the captured images of the inner wall of the conduit using thecamera and the positions of the position data generated throughmonitoring of the movement of the sled using the position encoder. Thestep of determining a capture position for at least a subset of theimages of the inner walls of the conduit captured by the cameracomprises uses the time stamps to associate images to correspondingcapture positions inside the conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages and characteristics will become more apparentupon reading the following non-restrictive description of embodimentsthereof, given for the purpose of exemplification only, with referenceto the accompanying drawings in which:

FIG. 1 (Prior Art) is a top plan view of a prior art conduit cleaningnozzle for cleaning a conduit and shown in operation for cleaning of aconduit.

FIGS. 2a to 2f are schematic representations of the components of aninspection system, in accordance with an embodiment, wherein thecomponents are positioned and moved along a sewer network during aninspection process in the course of FIGS. 2a to 2 f.

FIG. 3 is a top perspective view of an inspection sled of the inspectionsystem shown in FIGS. 2a to 2f , in accordance with an embodiment andwherein the inspection sled is being shown mounted to a cleaning nozzle.

FIG. 3a is a rear elevation view of the inspection sled of FIG. 3showing the camera and lights mounted on the camera mount of theinspection sled, in accordance with an embodiment.

FIG. 4 is a top perspective view of a position encoder of the inspectionsystem shown in FIGS. 2a to 2f , in accordance with an embodiment.

FIG. 5 is a top perspective view of an inspection sled of an inspectionsystem for inspection of a sewer network and mounted to a cleaningnozzle, in accordance with an embodiment where the displacement assemblyof the sled is provided with skis.

FIG. 6 is a top perspective view of an inspection sled in accordancewith an alternative embodiment where the connection member of theinspection sled is configured to be used in connection with a cleaningnozzle including an attachment loop.

FIG. 7 is a flowchart of the steps of the method for performinginspection of a sewer network in accordance with an embodiment.

DETAILED DESCRIPTION

In the following description, the same numerical references refer tosimilar elements. The embodiments, geometrical configurations, materialsmentioned and/or dimensions shown in the figures or described in thepresent description are embodiments only, given solely forexemplification purposes.

Although the embodiments of the system for the inspection of a sewernetwork consist of certain components as explained and illustratedherein, not all of these components are essential and thus should not betaken in their restrictive sense. It is to be understood, as alsoapparent to a person skilled in the art, that other suitable componentsand cooperation therein between, as well as other suitable geometricalconfigurations, can be used for the sewer network inspection system, aswill be briefly explained herein and as can be easily inferred herefromby a person skilled in the art.

Moreover, although the associated method includes steps as explained andillustrated herein, not all of these steps are essential and thus shouldnot be taken in their restrictive sense. It will be appreciated that thesteps of the method for inspection of a sewer line described herein canbe performed in the described order, or in any suitable order.

To provide a more concise description, some of the quantitative andqualitative expressions given herein can be qualified with the termssuch as “about” and “substantially”. It is understood that whether theterms “about” and “substantially” are used explicitly or not, everyquantity or qualification given herein is meant to refer to an actualgiven value or qualification, and it is also meant to refer to theapproximation to such given value or qualification that would reasonablybe inferred based on the ordinary skill in the art, includingapproximations due to the experimental and/or measurement conditions forsuch given value.

In accordance with the embodiments described in more details below,there is provided a system and a method for performing inspection of asewer network. As will become clear by reading the description below,the system is designed to take advantage of the components provided toperform the cleaning of the conduit, in order to perform the inspectionof at least a section of the conduit. The inspection is performed bymoving a camera longitudinally along a previously cleaned section of theconduit to simultaneously: A) capture images of the inner walls of thesection of the conduit; and B) continuously determine the position ofthe camera within the conduit section as images are being captured.

In the course of the description below, one skilled in the art willunderstand that while the system is described herein in reference tocleaning and inspecting of a “conduit”, the system could also be used toperform similar cleaning and/or inspection of a manhole in which thecomponents of the system are moved, with the system operating similarlyin “manholes” as in “conduits”. Hence, even though the system isdescribed in view of its operation for cleaning and inspecting“conduits”, the description below also extends to cleaning and/orinspection of “manholes” of a sewer network. In an embodiment, thesystem and method are designed to move a camera within a section ofconduit having previously been cleaned using the cleaning nozzleconnectable to a sled, which will be described in more details below.

In view of the above, one skilled in the art will understand that thesystem is designed to capture a combination of images (i.e. an image ora sequence of images, which can be continuous to define a video sequenceor discontinuous to present a series of distinct images) from inside thecleaned conduit. The simultaneous capture of the images anddetermination of the position of the camera capturing the images withinthe conduit, allows each image being captured to be associated to aspecific position in the conduit. In an embodiment conduit inspectionmetadata can also be generated during the inspection. The conduitinspection metadata can, for example and without being limitative beinputted manually by a user, be inputted by voice command by a user, beautomatically generated during the capture of the images by the system,be generated through a combination of manual input and automaticgeneration, etc.

In an embodiment, the captured images and the position data cansubsequently be stored in an inspection data database. The conduitinspection metadata associated to the captured images can beconcatenated (or joined) to the images in the inspection data database.One skilled in the art will understand that, in alternative embodiments,the conduit inspection metadata can also be stored in a distinctdatabase linked to the inspection data database, such that the conduitinspection metadata are associated to the corresponding images usinginterrelated databases.

In the course of the present description, for ease of description andconcision, the term “images” is used to refer to either a single imageor a sequence of images (which includes a video presenting a pluralityof successive images) showing the inside of a conduit. One skilled inthe art will also understand that the term “image” can also be used inthe present description to refer to a tridimensional representation ofthe inside of a conduit, such as, for example and without beinglimitative a point cloud. The term “image” can also be used to define acombination of a single image or a sequence of images (e.g. a video) andthe tridimensional representation of the inside of the conduit. It willbe understood that a point cloud can be generated using differentmethods and technologies such as, for example and without beinglimitative, by stereoscopy where processing of overlapping images isperformed to obtain the tridimensional representation of the inside ofthe conduit, using a 3D scanner scanning the inner surface of theconduit wall, etc. Hence, in the description below, it will beunderstood that any reference to a “camera” should be understood torefer more generally to imaging equipment and to include the possibilityof a single (or a plurality of) 360° cameras and/or a 3D scannerscanning the inner surface of the wall of the conduit, to generate apoint cloud.

One skilled in the art will understand that the captured images and theassociated position data and conduit inspection metadata cansubsequently be used to identify the presence (or absence) and theposition of conduit specific characteristics which can be identified inthe images and which are relevant for the description, and theevaluation of the condition and/or the performance of the conduit.

FIG. 1 (Prior Art) shows a conventional cleaning nozzle 20, such asthose currently used to alter the direction of flow and velocity of thewater and perform hydro-jet cleaning of conduits. The cleaning nozzle 20includes fluid outlets 22 from which high-pressured jets 24 of water areprojected as the nozzle 20 is moved within a conduit, to remove buildupsand debris inside the conduit. One skilled in the art will understandthat the shape and/or size of the cleaning nozzle 20, as well as theposition, angles and size of the fluid outlets 22 can vary, for exampleand without being limitative, to be adapted to specific cleaningapplications and/or to the conduit to be cleaned. In many cases,different nozzles 20 can be used successively to perform cleaning of aconduit.

In order to be provided with a water flow, the nozzle 20 is connected toa hose 52. In an embodiment, the hose 52 is connected to apressure-washing apparatus (not shown) including a pump (not shown)generating water pressure and feeding a high-pressure water flow intothe hose 52 and to the nozzle 20. The pressure washing apparatus can beconnected to a water source using a second distinct hose (not shown).For example and without being limitative, in an embodiment, the pressurewashing apparatus (not shown) can be installed in a cleaning vehiclemovable to the location of the conduit to be cleaned.

In FIG. 1, a rigid pipe section 25 is shown connected to the nozzle 20.In such an embodiment. The hose 52 is connected to a distal end 25 b ofthe pipe section 25, with the proximal end 25 a of the pipe section 25being connected to the nozzle 20.

One skilled in the art will understand that the cleaning nozzle 20 canbe used in combination with a vacuum (not shown) operating to suctionand remove the dislodged buildups and debris from the conduit. In anembodiment, the vacuum can be connected to a collection tank receivingand storing the collected buildups and debris.

General Description of the System

Now referring to FIGS. 2a to 3a there is shown an embodiment of theinspection system 110, wherein the features are numbered with referencenumerals in the 100 series, which correspond to the reference numeralsof the prior art elements described above.

The inspection system 110 includes an inspection sled 130 havinginspection equipment mounted thereto and being insertable and movableinside a conduit 170, for inspection of an inner portion 172 thereof.The inspection sled 130 and the inspection equipment mounted theretowill be described in more details below. The inspection sled 130 isconnectable to a cleaning nozzle 120 movable inside a conduit 170 forperforming cleaning thereof. In an embodiment, after the cleaning of theconduit 170 has been performed using the cleaning nozzle 120, theretraction movement of the nozzle 120 can be used to drive the sled 130inside the conduit 170 to perform inspection thereof. Indeed, in anembodiment, the inspection sled 130 is configured to be engaged by thecleaning nozzle 120, once the cleaning nozzle 120 has been moved forwardinside the conduit 170 for the last time in the process of cleaning theconduit 170, as will be described in more details below. Therefore, inthe embodiment shown, after being connected to the cleaning nozzle 120,the inspection sled 130 can be moved inside the conduit 170 to performinspection thereof, as the cleaning nozzle 120 is retracted to beremoved from the conduit 170. Once again, the connection mechanism forconnecting the cleaning nozzle 120 to the inspection sled 130 will bedescribed in more details below.

One skilled in the art will however understand that, in alternativeembodiments (not shown), the inspection sled 130 could also be connectedto the cleaning nozzle 120 as the cleaning nozzle 120 is moved insidethe conduit 170 to perform the cleaning thereof. In an embodiment, theinspection sled 130 could be moved inside the conduit 170 to performinspection thereof, as the cleaning nozzle 120 is moved inside theconduit 170 (either forwards or rearward) in the process of cleaning theconduit 170.

In the embodiment shown, the inspection system 110 also includes aposition encoder 160 working in combination with the hose 152 onto whichthe cleaning nozzle 120 is mounted. Hence, when the hose 152 is movedalong with the movement of the nozzle 120 in the conduit (and drive thesled 130 inside the conduit 170), the movement of the hose 152 can betracked by the position encoder 160, to determine the movement (andincidentally the position) of the nozzle 120 and the sled 130 connectedthereto inside the conduit 170. Once again, the position encoder 160will be described in more details below. It will also be understoodthat, in an alternative embodiment, the position encoder 160 could beconfigured to track the movement of the nozzle 120 (and incidentally themovement of the inspection equipment mounted onto the sled 130) bytracking the rotation of a rotative shaft rotating along with themovement of the sled 130, such as, for example, a rotative shaft of awheel of the sled 130, or the like.

Positioning and Movement of the Components Inside the Conduit

Referring more particularly to FIGS. 2a to 2f , an embodiment where theinspection sled 130 is configured to be engaged by the cleaning nozzle120 once the cleaning nozzle 120 has been moved forward inside theconduit 170 for the last time in the process of cleaning the conduit 170is shown. In the embodiment shown, a pressure-washing apparatus (notshown) is installed in a cleaning vehicle 150 movable in proximity to afirst manhole 151 a (or any other access conduit) allowing access to theconduit 170 to be inspected.

Hence, as shown more clearly in FIG. 2a , the cleaning nozzle 120 andthe associated hose 152 onto which the nozzle 120 is mounted can beinserted into the conduit 170 and the cleaning nozzle 120 can be movedback and forth inside the conduit 170 to perform cleaning thereof. Oncethe cleaning nozzle 120 has been circulated back and forth inside theconduit 170 a sufficient number of times to perform the desiredcleaning, the nozzle 120 can be moved forward inside the conduit 170 onelast time, until it reaches a position located proximate to the outletof a second manhole 151 b distant from the first manhole 151 b.

As shown more clearly in FIG. 2b , in the embodiment shown, the sled 130can be lowered into the conduit 170 via the second manhole 151 b,simultaneously with the cleaning of the conduit or subsequently thereto.Hence, the sled 130 is introduced in the conduit 170 in a locationremote from the first manhole 151 a in which the hose 152 and thecleaning nozzle 120 were originally introduced and from which the hose152 protrudes. In the embodiment shown, the inspection sled 130 can belowered in the second manhole 151 b using a pole selectively connectableto the sled 130 using a pole electromagnet 154. In the embodiment shown,the electromagnet 154 is positioned at an extremity of the pole 153 andis connectable to a magnetic section 133 of the sled 130 configured toconnect with a magnet. One skilled in the art will understand that, inan alternative embodiment (not shown), the electromagnet could rather beplaced on the sled 130, to connect with a magnetic end of the pole 153.It will also be understood that, in other alternative embodiments (notshown), different temporary connecting means could be used toselectively connect the sled 130 with the pole 153. Furthermore, inother alternative embodiments a different component than a pole, suchas, for example and without being limitative, a rope or the like, couldbe used to lower the sled 130 in the conduit, through the second manhole151 b.

In the embodiment shown, the electromagnet 154 can be activated toengage the pole 153 with the magnetic section 133 of the sled 130 andmaintain the two objects connected, while the pole 153 is used to lowerthe sled 130 through the second manhole 151 b and in the conduit 170.

As shown more clearly in FIGS. 2c and 2d , in an embodiment, once thesled 130 is in place, the nozzle 120 can be moved forward inside theconduit 170 towards the sled 130, until it reaches the sled 130 andconnects therewith. The sled 130 includes a nozzle connecting section140 configured to selectively connect the nozzle 120 to the sled andmaintain the nozzle 120 and the sled 130 attached to one another for adesired period of time. In the embodiment shown, the nozzle mountingsection 140 includes a nozzle electromagnet 141 activable to attract thenozzle 120 and temporarily connect the nozzle 120 with the nozzleelectromagnet 141. The sled 130 and its nozzle connecting section 140will be described in more details below. For example and without beinglimitative, in an embodiment, the nozzle electromagnet 141 (or othercorresponding electromagnet) can be activated/deactivated using aremote-control system (not shown).

It should be noted that one skilled in the art will understand that, inalternative embodiments (not shown), the electromagnet can be placed onthe nozzle 120 rather than the sled 130 or that other assemblies ormethod, differing from the described electromagnet could be used toselectively and temporarily connect the sled 130 with the nozzle 120.

In the embodiment shown, once the sled 130 is in place and the nozzle120 is mounted to the nozzle connecting section 140 of the sled 130, thepole electromagnet 154 can be deactivated to disconnect the pole 153from the sled 130 and the pole 153 can be withdrawn, with the sled 130being left in the conduit 170, close to the outlet of the second manhole151 b. Once again, for example and without being limitative, in anembodiment, the electromagnet 154 can be deactivated using aremote-control system (not shown).

As shown more clearly in FIG. 2e , once the nozzle 120 is joined to thenozzle connecting section 140 of the sled 130, the sled 130 can bedriven by the movement of the nozzle 120 being retracted (e.g. beingmoved back towards the cleaning vehicle 150 in the embodiment shown), tomove the sled 120 along the conduit 170 (i.e. along the section of theconduit 170 defined between the second manhole 151 b and the firstmanhole 151 a). In other words, in the embodiment shown, the hose 152onto which the nozzle 120 is mounted can be winded back, to retrieve thenozzle 120 and move the sled 130 attached thereto along the conduits170, towards the cleaning vehicle 150.

During the movement of the sled 130 inside the conduit 170, the camera136 mounted on the sled 130 can be activated to capture images of theinner portion 172 (or inner walls) of the section of the conduit 170.Once again, for example and without being limitative, in an embodiment,the camera 136 can be activated/deactivated using a remote-controlsystem (not shown).

Simultaneously to the capture of the images by the camera 136, thesystem 110 is configured to record the position of the sled 130 (and thecamera 136 mounted thereon) inside the conduit 170, such that the imagescaptured can be associated to a corresponding location inside theconduit 170. In an embodiment, the position is determined using a rotaryposition encoder 160 mounted on the cleaning vehicle 150 and brought inrotation by the movement of the hose 152. Therefore, when the hose 152is moved, the movement of the hose 152 produces rotation of a main shaft162 of the position encoder 160, which can subsequently be used todetermine the movement of the sled 130 and its corresponding positionover time. For example and without being limitative, in an embodiment,the camera 136 and the position encoder 160 are configured to generatetime stamps. The corresponding time stamps associated to positionsdetermined using the position encoder 160 and to images captured by thecamera 136 are used to associate images to corresponding positions (orcoordinates). One skilled in the art will understand that, in anembodiment the data generated by additional components of the inspectionequipment mounted onto the sled 130 could generate time stamp also beingused to associate images to corresponding positions (or coordinates).

Now referring to FIG. 2f , once the sled 130 has reached the firstmanhole 151 a, the sled 130 can be brought back up in the first manhole151 a to be retrieved. In an embodiment, the inspection is ended oncethe sled 130 has reached the first manhole 151 a and before the sled 130is brought back up inside the first manhole 151 a by further winding upof the hose 152 and the corresponding movement of the nozzle 120. In analternative embodiment, inspection of the first manhole 151 a can alsobe performed as the sled 130 is brought back up inside the first manhole151 a, by further winding up of the hose 152.

As previously mentioned, one skilled in the art will understand that, inalternative embodiments (not shown), the inspection sled 130 could bemounted to the cleaning nozzle 120 at a different point in time thanwhat is described in the embodiment above and could be introduced intothe sewer network from a different point of entrance than the secondmanhole 151 b. Similarly, inspection could be performed concurrentlywith the cleaning of the conduit 170 by the cleaning nozzle 120.

Components of the System

Now referring to FIGS. 3 to 4, the components of the system 110 will bedescribed in more details below.

FIG. 3 shows in more details, the inspection sled 130 which isinsertable in the conduit 170 and connectable to the nozzle 120. Theinspection sled 130 has a sled frame 132 defining a sled body 131 ontowhich the inspection elements are mounted.

The sled 130 also includes a displacement assembly 137 mounted to thesled frame 132 and supporting the frame 132 on the ground, to allow easymovement of the sled 130 along the conduit 170. In the embodiment shown,the displacement assembly 137 includes a plurality of wheels 137 a, butone skilled in the art will understand that, in alternative embodiments,other elements favoring the displacement of the sled 130, such as skis,tracks, or the like, could be used as part of the displacement assembly.

The sled 130 also includes a camera mount 138 mounted to the frame 132.In the embodiment shown, the camera mount 138 is positioned, at a rearend 131 a of the sled body 131, but one skilled in the art willunderstand that, in alternative embodiments (not shown), it could bepositioned at a different position. The camera mount 138, has a mountingframe 138 a sized and shaped to receive a camera 136 and lights 139. InFIG. 3, the camera mount 138 is shown free of camera and lights. FIG. 3ashows an embodiment of the camera mount 138 having a camera 136 andlights 139 mounted thereon. The mounting frame 138 a is made of amaterial strong enough to support the camera 136 and the lights 139 andcapable of resisting the heat generated by the lights 139 without beingdamaged. For example and without being limitative, in an embodiment themounting frame can be made of aluminum, steel, polymer material offeringa sufficient rigidity and heat resistance, etc.

The camera 136 and lights 139 are configured to capture images of thesurroundings of the inspection sled 130 and can be any type of cameraand/or light available on the market with characteristics adapted toallow the capture of the images in a corresponding conduit. For exampleand without being limitative, in an embodiment, the camera 136 can be a360° camera, such as, for example and without being limitative a GoPro™Max camera, a combination of two 180° cameras facing oppositedirections, or the like. In an embodiment, the camera 136 could ratherbe embodied by a 3D scanner, such as for example and without beinglimitative a LiDAR scanner, a laser profiler, or other equipmentallowing 3D scanning. In an embodiment the camera 136 could also beembodied by a combination of the above mentioned 360° degree camera,combination of 180° degree cameras and a 3D scanner.

The lights 139 are lights lighting at least a portion of the field ofview of the camera 136 and providing a lighting capacity appropriate forthe capture of clear images by the camera 136 in the dark environment ofthe conduit 170. Hence, the lights 139 are selected and oriented toprovide a sufficient lighting power, adapted beam lights and a goodwhite balance for the capture of the images inside the conduit 170. Forexample and without being limitative, in an embodiment (not shown), acombination of a LED lighting apparatus 139 a providing flood lightingin the proximity of the camera 136 and focalized lights 139 b providingfocalized lighting further away from the camera 136, in the field ofview thereof, can be used. One skilled in the art will understand that,in alternative embodiments (not shown), other lighting combination canbe used. It will also be understood that, in an embodiment (not shown),the lights 139 can be mounted to the frame 132 of the sled 130 or onto acombination of the frame 132 of the sled 130 and the camera mount 138.

In the embodiment shown, the sled 130 further includes a nozzle mountingsection 140. The nozzle mounting section 140 is positioned, at a frontend 131 b of the sled body 131 (i.e. at an end of the body engageablewith the nozzle 120 and being the leading end of the sled 130 when thesled 130 is moved inside the conduit by the movement of the nozzle 120),and is configured to be engageable by the nozzle 120. In the embodimentshown in FIG. 3, the nozzle mounting section 140 includes an engagementbody 142 projecting forward from the sled body 131 and positioned, sizedand shaped to selectively engage with the nozzle 120. In the embodimentshown, the nozzle mounting section 140 includes a nozzle electromagnet141 at a forward end thereof. The nozzle electromagnet 141 is activableto attract the nozzle 120 and temporarily connect the nozzle 120 withthe engagement body 142 of the sled 130 and deactivable to break theconnection therebetween.

In the embodiment shown in FIG. 3, the engagement body 142 is pivotallymounted to the sled body 131, using a hinge 143 allowing upward pivotingof the engagement body 142. The pivotal connection between theengagement body 142 and the sled body 131 can help the transition of thesled from the conduit 140 to the first manhole 151 a, when the sled 130is being retrieved from the conduit 170 (as described in more detailedabove in connection with FIG. 2f ). It will be understood that, in analternative embodiment (not shown) the engagement body 142 could berigidly mounted to the sled body 131. In another alternative embodiment(not shown), the engagement body 142 could be pivotally mounted to thesled body 131, using a rotative connection allowing movement along a360° range, amongst other things, to help minimize the effect of thetwist in the hose 152 on the sled 130.

In the embodiment shown, the engagement body 142 further includes aguiding funnel 144 projecting forward from the engagement body 142, atthe front end thereof. The guiding funnel 144 is centered on the nozzleelectromagnet 141 and reduces in size as it gets closer to it. Hence,when the nozzle 120 approaches the sled 130 positioned in the conduit140, the funnel 144 guides the nozzle 120 towards the electromagnet 141to ease the connection of the two components.

Referring again to FIG. 3, In an embodiment, the sled 130 includes amagnetic section 133 configured to connect with the electromagnet of theguiding pole (as described in more details above). As already mentioned,in an alternative embodiment, the electromagnet for magnetic connectionwith the pole 153 can be provided on the sled 130.

In an embodiment, the sled 130 also includes a battery 146. The battery146 can be connected to the components requiring power, such as, forexample and without being limitative, the camera 136, the lights 139,the nozzle electromagnet 141 or the like.

In an embodiment, the sled 130 can also include an inertial measurementunit (IMU) including components such as, for example and without beinglimitative, accelerometers, gyroscopes, magnetometers, to monitor theand report the force, angular rate and/or orientation of the sled 130 asit is moved inside the conduit.

In an embodiment, the sled 130 can also include a battery 146. Thebattery 146 can be connected to the components requiring power, such as,for example and without being limitative, the camera 136, the lights139, the nozzle electromagnet 141 or the like.

In an embodiment, the sled 130 can further include an audio recordingassembly allowing recording of the sounds of the surrounding of the sled130, for example to allow an operator to record data relative to whichconduit is being inspected or is going to be inspected by the sled 130.

In an embodiment, a computer 147 (or computing unit) could also beprovided on the sled 130, for example to allow remote control of thecomponents mounted on the sled 130, such as the camera 136, the lights139, the nozzle electromagnet 135 or the like. In an embodiment, thecomputer 147 can include storage medium for storing data. In analternative embodiment, additional storage medium distinct from thestorage medium of the computer 147 can also be provided. Hence the dataacquired by the components of the inspection sled 130, such as thecamera 136 or the like, can be stored in the storage medium forsubsequent transfer to an external processing unit (not shown)processing the data acquired using the components of the inspection sled130 (i.e. transfer to the external processing following extraction ofthe inspection sled 130 from the conduit, for example using short rangecommunication, wired connection, or the like). In an alternativeembodiment, the data acquired by the components of the inspection sled130 can be transmitted to an external processing unit in real time (ornear real time) through a wired connection running along the hose 152 ofthe system, or through wireless connection, for example using connectionrelays positioned inside the conduit.

In an alternative embodiment, other mechanism or methods could be usedto remotely or mechanically activate/deactivate the components.

Now referring to FIG. 4, the position encoder 160 of the inspectionsystem 110 is shown, in accordance with an embodiment. In an embodiment,the position encoder 160 is mounted proximal to the source of the hose152 to which the cleaning nozzle 120 is connected. In the embodimentshown, the position encoder 160 is mounted to the cleaning vehicle 150.

One skilled in the art will however understand that, in an alternativeembodiment, the position encoder 160 could be positioned to engage thehose 152 at any position along the hose 152 which allows monitoring ofthe movement of the hose 152. Hence, it can be mounted to any structureor element allowing the position encoder 160 to be held in place as thehose is winded/unwinded and engages the position encoder 160.

One skilled in the art will also understand that, in alternativeembodiments (not shown), the position encoder 160 could monitor themovement of an element different than the hose 152 in order to monitorthe movement of the sled 130, to determine its corresponding positionover time. For example and without being limitative, the positionencoder 160 can be mounted directly on the sled 130, and be configuredto monitor the movement of the corresponding nozzle 120 and the sled 130connected thereto (along with the camera 136 mounted onto the sled 130)within the conduit 170, through measuring of a rotative movement of arotative member of the displacement assembly 137 rotating along with themovement of the sled 130 inside the conduit 170. For instance, theposition encoder can monitor the rotation of a wheel (or a shaftthereof) indicative of the movement of the sled 130, or the like.

In the embodiment shown, the position encoder 160 includes a main shaft162 rotatable by the movement of the hose 152 circulating in theposition encoder 160 and the necessary components such as, detectors,electronics, circuitry and the like for providing feedback regarding theposition and/or movement of the main shaft 162. Rotary encoders areknown in the art and one skilled in the art will understand thatnumerous types of rotary encoders could be used as part of the presentinspection system 110, to monitor the position of the camera 136 withinthe conduit 140. For example and without being limitative, one skilledin the art will understand that the position encoder 160 can be anabsolute rotary encoder or an incremental rotary encoder.

In the inspection system 110, the angular movement (or the angularposition) of the main shaft 162 is used to determine the movement of thehose 152 and consequently the movement of the corresponding nozzle 120and the sled 130 connected thereto within the conduit 140. Given thatthe camera 136 is mounted on the sled 130, the movement of the camera136 can be continuously determined using the data of the positionencoder 160, as will be described in more details below.

In the embodiment shown, the position encoder 160 includes a main body164 attachable to a section of the cleaning vehicle 150. The main shaft162 is rotatably mounted relative to the main body 164. The positionencoder 160 also includes a biasing pulley 166 biased towards the mainshaft 162 by a biasing assembly 167, in order to bias the hose 152towards the main shaft 162. In other words, a free space is definedbetween the main shaft 162 and the biasing pulley 166 for the hose 152to move therebetween. To ensure a sufficient contact between the hose152 and the main shaft 162 to drive the main shaft 162 in rotation whenthe hose 152 is moved thereabout, the biasing pulley 166 is pressedtowards the main shaft 162 by springs 168 of the biasing assembly 167and presses the hose 152 onto the main shaft 162.

As described above, when the hose 152 is moved and drives the sled 130inside the conduit 170 (e.g. when the hose is pulled to remove (orwithdraw) the nozzle 120 from the conduit 170), the movement of the hose152 can therefore be tracked by the position encoder 160, to determinethe movement (and incidentally the position) of the nozzle 120 and thesled 130 connected thereto inside the conduit 170.

In view of the above, the combination of the position encoder 160monitoring the movement of the hose 152 and the camera 136 being mountedon the sled 130 moved concurrently with the movement of the hose 152,allows the simultaneous capture of the images and determination of theposition of the camera 136 within the conduit. Hence, each capturedimage can be associated to a position in the conduit 170. In anembodiment, the position encoder 160 and the camera 136 can be used tocollect data to be subsequently imported to a computer (not shown) whichprocesses the position data from the position encoder 160 and the imagesfrom the camera 136 to generate the images with the associated position.One skilled in the art will understand that, as previously described,any mean or method which allow data communication between the camera136, position encoder 160 and the external computer (or processing unit)can be used, such as, wired or wireless connection over a network,importation of data using external data storage such as memory cards, orthe like. As previously mentioned, conduit inspection metadata can alsobe generated, and the images and the position data can subsequently bestored in an inspection data database.

It will be understood that different types of inspection sleds capableof receiving the necessary equipment (camera 136, lights 139, battery146, computer 147, IMU, audio recording assembly, engagement body 142,nozzle electromagnet 141, etc.) could be used, for example to adapt todifferent conduit sizes, configurations conditions, etc. One skilled inthe art will understand that the design and configuration of the sled130 should favor insertion/retrieval of the sled 130 in thecorresponding manholes 151 a, 151 b, easy connection of the nozzle 120with the nozzle mounting section 140, quality of the images capturedduring inspection and maneuverability and stability of the sled 130 inthe conduit 140 during displacement.

For example and without being limitative, FIG. 5 shows a sled 230 inaccordance with an alternative embodiment of the inspection system,wherein the features are numbered with reference numerals in the 200series, which correspond to the reference numerals of the previousembodiment described above. In the embodiment of FIG. 5, the sled 230 isprovided with a displacement assembly 237 with skis 137 b instead of thewheels shown in FIG. 3 and being more compact. It will be understoodthat only partial equipment, and only the camera mount, without thecamera and lights, is shown on the sled 230 of FIG. 5, but the sled 230could include all the equipment of the sled shown in the previousembodiment.

FIG. 6 shows a sled 330 in accordance with an alternative embodiment ofthe inspection system, wherein the features are numbered with referencenumerals in the 300 series, which correspond to the reference numeralsof the previous embodiment described above. In FIG. 6, a sled having analternative connection assembly for selectively connecting the nozzle320 to the sled 330 is shown. In the embodiment of FIG. 6, the nozzle320 is provided with an attachment loop 326 at the attachment endthereof. The nozzle mounting section 340 of the sled 330 includes anattachment bracket 345 (rather than the previously described nozzleelectromagnet) onto which the attachment loop 326 of the nozzle 320 issecurable, by insertion of a locking pin 345 a of the attachment bracket345 into the attachment loop 326 of the nozzle 320. For example andwithout being limitative, the insertion of the locking pin 345 a intothe attachment loop 326 of the nozzle 320 can be performed by anoperator to secure the nozzle 320 to the sled 330.

The inspection system having been described in detail above, the methodfor inspection of a conduit will now be described in more details belowin reference to FIG. 7.

As previously mentioned, in an embodiment the method 400 includes theinitial step 410 of inserting a cleaning nozzle in a conduit to beinspected and cleaning the conduit by movement of the cleaning nozzletherein. In other words, this steps is performed by inserting the andmoving the cleaning nozzle in the conduit to be inspected in order toperform cleaning of the conduit, the cleaning nozzle being mounted on ahose. In an embodiment, the nozzle is inserted in the conduit through afirst manhole.

The method also includes the step 420 of inserting an inspection sledhaving inspection material mounted thereon in the conduit, using asecond manhole. In an embodiment, this step includes the sub steps ofengaging the sled to a guiding pole (or other elements allowingcontrolled lowering of the sled), lowering the sled in the conduit usingthe guiding pole and disengaging the guiding pole from the sled. In anembodiment, the substep of engaging the sled to a guiding pole includesactivating a pole engaging electromagnet and the substep of disengagingthe guiding pole from the sled includes deactivating the pole engagingelectromagnet.

The method also includes the step 430 of engaging the cleaning nozzlewith the sled and the further step 440 of moving the moving the guidingnozzle (through movement of the hose onto which the cleaning nozzle ismounted) inside the conduit to correspondingly move the engaged sled inthe conduit. Simultaneously to the sled being moved in the conduit, themethod includes the step 450 of capturing images of the inner wall ofthe conduit using a camera mounted on the sled.

In an embodiment, the step 440 of moving the hose inside the conduitincludes winding back the hose to retrieve the guiding nozzle and movethe engaged sled in the conduit.

In an embodiment, the step 430 of engaging the cleaning nozzle to thesled includes activating a nozzle electromagnet to bias the nozzletowards the nozzle mounting section of the inspection sled and maintainthe nozzle in engagement therewith. In an embodiment, this step 430 alsoincludes advancing the nozzle towards the sled and guiding the nozzleusing a funnel.

Simultaneously to the capture of images by the camera, the method alsoincludes the step 460 of acquiring position data through monitoring ofthe movement of the hose being winded back using a position encoder. Themethod further includes the step 470 of determining a capture positionfor at least a subset of the images of the inner walls of the conduitcaptured by the camera, using the position data.

In an embodiment, this step includes generating time stamps for thecaptured images of the inner wall of the conduit using the camera andthe positions of the position data generated through monitoring of themovement of the sled using the position encoder, and using the timestamps to associate images to corresponding capture positions inside theconduit. Once again, one skilled in the art will understand that, in anembodiment, this step could include generating time stamps for the datagenerated by additional components of the inspection equipment mountedonto the sled and using the time stamps to associate images tocorresponding positions (or coordinates).

In an embodiment, the method further includes removing the sled from theconduit, via the first manhole. In an embodiment, this step is performedsimply by winding back the hose until the sled is removed from theconduit via the first manhole. In an embodiment, this step can includethe sub steps of: capturing images of the inner wall of the firstmanhole using the camera mounted on the sled, acquiring position datathrough monitoring of the movement of the sled using the positionencoder; and determining a capture position for at least a subset of theimages of the inner walls of the first manhole captured by the camera,using the position data, being performed simultaneously to the sledbeing moved in the first manhole.

Several alternative embodiments and examples have been described andillustrated herein. The embodiments of the invention described above areintended to be exemplary only. A person of ordinary skill in the artwould appreciate the characteristics of the individual embodiments, andthe possible combinations and variations of the components. A person ofordinary skill in the art would further appreciate that any of theembodiments could be provided in any combination with the otherembodiments disclosed herein. It is understood that the invention couldbe embodied in other specific forms without departing from the centralcharacteristics thereof. The present examples and embodiments,therefore, are to be considered in all respects as illustrative and notrestrictive, and the invention is not to be limited to the details givenherein. Accordingly, while the specific embodiments have beenillustrated and described, numerous modifications come to mind. Thescope of the invention is therefore intended to be limited solely by thescope of the appended claims.

1. A system for inspection of a sewer network, the system comprising: acleaning nozzle mounted on a hose; an inspection sled having a cameramounted thereon and a nozzle mounting section selectively engageable tothe cleaning nozzle; and a position encoder configured to acquireposition data representative of the position of the camera inside theconduit while the sled is moved inside the conduit by the movement ofthe cleaning nozzle and the camera captures images of the inner wall ofthe conduit.
 2. The system of claim 1, wherein the position encoder isconfigured to determine the position of the camera inside the conduitthrough measuring of the movement of the hose as the nozzle is movedinside the conduit, the hose being extended and retractedcorrespondingly in accordance with the movement of the nozzle inside theconduit.
 3. The system of claim 2, wherein the position encoder ismounted on a cleaning vehicle, the hose being connected to the cleaningvehicle and being selectively extended from the cleaning vehicle andwinded back towards the cleaning vehicle in accordance with the forwardand rearward movement of the nozzle inside the conduit, the movement ofthe hose being representative of the movement of the inspection sledinside the conduit, when the inspection sled is engaged to the cleaningnozzle.
 4. The system of claim 1, wherein the position encoder ismounted on the inspection sled, the position encoder being configured todetermine the position of the camera inside the conduit throughmeasuring of a rotative movement of a rotative member of a displacementassembly rotating along with the movement of the sled inside the conduitinduced by the movement of the cleaning nozzle.
 5. The system of claim1, wherein the nozzle mounting section includes an electromagnetactivable to engage the cleaning nozzle to the nozzle mounting sectionof the sled.
 6. The system of claim 5, wherein the nozzle mountingsection includes a guiding funnel projecting at a front end of thenozzle mounting section, the guiding funnel being centered on theelectromagnet.
 7. The system of claim 1, wherein the sled includes asled body and the nozzle mounting section includes an engagement bodypivotally mounted to the sled body, using a hinge allowing pivoting ofthe engagement body with regard the sled body.
 8. The system of claim 1,wherein the inspection sled further comprises lights configured toprovide lighting of a at least a portion of a field of view of thecamera.
 9. The system of claim 1, wherein the camera and the positionencoder are configured to generate time stamps, the corresponding timestamps associated to positions determined using the position encoder andto images captured by the camera being used to associate images tocorresponding positions inside the conduit.
 10. A method for inspectionof a sewer network, the method comprising the steps of: moving acleaning nozzle in a conduit to be inspected, the cleaning nozzle beingmounted to a hose, at an end thereof; inserting a sled having inspectionmaterial mounted thereon in the conduit, the inspection materialincluding a camera; engaging the cleaning nozzle with the sled; movingthe guiding nozzle in the conduit and correspondingly moving the engagedsled in the conduit; and simultaneously to the sled being moved in theconduit by the movement of the guiding nozzle: capturing images of theinner wall of the conduit using the camera mounted on the sled; andacquiring position data through monitoring of the movement of the sledusing a position encoder; and determining a capture position for atleast a subset of the images of the inner walls of the conduit capturedby the camera, using the position data.
 11. The method of claim 10,further comprising the steps of inserting the cleaning nozzle in theconduit through a first manhole and inserting the inspection sled in theconduit via a second manhole.
 12. The method of claim 10, wherein thestep of acquiring position data through monitoring of the movement sledusing a position encoder comprises monitoring the movement of the hose.13. The method of claim 10, wherein the step of inserting the sled inthe conduit comprises the sub steps of: engaging the sled to a guidingpole; lowering the sled in the conduit using the guiding pole; anddisengaging the guiding pole from the sled.
 14. The method of claim 13,wherein the sub step of engaging the sled to a guiding pole includesactivating a pole engaging electromagnet and the sub step of disengagingthe guiding pole from the sled includes deactivating the pole engagingelectromagnet.
 15. The method of claim 10, wherein the step of engagingthe cleaning nozzle to the sled includes activating a nozzleelectromagnet.
 16. The method of claim 15, wherein the step of engagingthe cleaning nozzle to the sled includes advancing the nozzle towardsthe sled and guiding the nozzle using a funnel.
 17. The method of claim10, further comprising the step of removing the sled from the conduit,via the first manhole.
 18. The method of claim 17, further comprisingthe steps of: simultaneously to the sled being moved in the firstmanhole: capturing images of the inner wall of the first manhole usingthe camera mounted on the sled; and acquiring position data throughmonitoring of the movement of the sled using the position encoder; anddetermining a capture position for at least a subset of the images ofthe inner walls of the first manhole captured by the camera, using theposition data.
 19. The method of claim 10, further comprising theinitial step of circulating the cleaning nozzle in the conduit in orderto perform cleaning of the conduit.
 20. The method of claim 10, furthercomprising generating time stamps for the captured images of the innerwall of the conduit using the camera and the positions of the positiondata generated through monitoring of the movement of the sled using theposition encoder, and wherein the step of determining a capture positionfor at least a subset of the images of the inner walls of the conduitcaptured by the camera comprises using the time stamps to associateimages to corresponding capture positions inside the conduit.